PHILADELPHIA (CBS) — The City of Philadelphia has declared a “Code Blue” ahead of what could be the coldest week of the year in the Delaware Valley.

Usually a Code Blue is called when some kind of snow or rain is expected to come along with the frigid temperatures, but in a situation like this, where the temperatures are expected to stay below 30-degrees, with the low 20s and teens common at night, city officials feel it’s necessary to try to get the homeless off the streets and into a shelter.

Leticia Egea-Hinton, Deputy Director of the Philadelphia Office of Supportive Housing says there is an even greater concern for homeless people with health issues.

“People who are chronically street homeless have a tendency to be a little sicker than other people,” she says, “so they may be dealing with medical issues that make them more vulnerable to the elements.”

City officials are encouraging anyone who sees a person living or sleeping on the street during the Code Blue to call 215-232-1984 to have workers come and check on the person.